dt-bindings: npu: rockchip,rknn: Add bindings

Add the bindings for the Neural Processing Unit IP from Rockchip.

v2:
- Adapt to new node structure (one node per core, each with its own
IOMMU)
- Several misc. fixes from Sebastian Reichel

v3:
- Split register block in its constituent subblocks, and only require
the ones that the kernel would ever use (Nicolas Frattaroli)
- Group supplies (Rob Herring)
- Explain the way in which the top core is special (Rob Herring)

v4:
- Change required node name to npu@ (Rob Herring and Krzysztof Kozlowski)
- Remove unneeded items: (Krzysztof Kozlowski)
- Fix use of minItems/maxItems (Krzysztof Kozlowski)
- Add reg-names to list of required properties (Krzysztof Kozlowski)
- Fix example (Krzysztof Kozlowski)

v5:
- Rename file to rockchip,rk3588-rknn-core.yaml (Krzysztof Kozlowski)
- Streamline compatible property (Krzysztof Kozlowski)

v6:
- Remove mention to NVDLA, as the hardware is only incidentally related
(Kever Yang)
- Mark pclk and npu clocks as required by all clocks (Rob Herring)

v7:
- Remove allOf section, not needed now that all nodes require 4 clocks
(Heiko Stübner)

v8:
- Remove notion of top core (Robin Murphy)

Signed-off-by: Sebastian Reichel <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Tested-by: Heiko Stuebner <[e-mail]>
Signed-off-by: Tomeu Vizoso <[e-mail]>
Reviewed-by: Rob Herring (Arm) <[e-mail]>
Signed-off-by: Jeff Hugo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/devicetree/bindings/npu/rockchip,rk3588-rknn-core.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/npu/rockchip,rk3588-rknn-core.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Neural Processing Unit IP from Rockchip
+
+maintainers:
+  - Tomeu Vizoso <[e-mail]>
+
+description:
+  Rockchip IP for accelerating inference of neural networks.
+
+  There is to be a node per each NPU core in the SoC, and each core should reference all the
+  resources that it needs to function, such as clocks, power domains, and resets.
+
+properties:
+  $nodename:
+    pattern: '^npu@[a-f0-9]+$'
+
+  compatible:
+    enum:
+      - rockchip,rk3588-rknn-core
+
+  reg:
+    maxItems: 3
+
+  reg-names:
+    items:
+      - const: pc # Program Control-related registers
+      - const: cna # Convolution Neural Network Accelerator registers
+      - const: core # Main NPU core processing unit registers
+
+  clocks:
+    maxItems: 4
+
+  clock-names:
+    items:
+      - const: aclk
+      - const: hclk
+      - const: npu
+      - const: pclk
+
+  interrupts:
+    maxItems: 1
+
+  iommus:
+    maxItems: 1
+
+  npu-supply: true
+
+  power-domains:
+    maxItems: 1
+
+  resets:
+    maxItems: 2
+
+  reset-names:
+    items:
+      - const: srst_a
+      - const: srst_h
+
+  sram-supply: true
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - clock-names
+  - interrupts
+  - iommus
+  - power-domains
+  - resets
+  - reset-names
+  - npu-supply
+  - sram-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/rockchip,rk3588-cru.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/power/rk3588-power.h>
+    #include <dt-bindings/reset/rockchip,rk3588-cru.h>
+
+    bus {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      npu@fdab0000 {
+        compatible = "rockchip,rk3588-rknn-core";
+        reg = <0x0 0xfdab0000 0x0 0x1000>,
+              <0x0 0xfdab1000 0x0 0x1000>,
+              <0x0 0xfdab3000 0x0 0x1000>;
+        reg-names = "pc", "cna", "core";
+        clocks = <&cru ACLK_NPU0>, <&cru HCLK_NPU0>,
+                 <&scmi_clk SCMI_CLK_NPU>, <&cru PCLK_NPU_ROOT>;
+        clock-names = "aclk", "hclk", "npu", "pclk";
+        interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH 0>;
+        iommus = <&rknn_mmu_0>;
+        npu-supply = <&vdd_npu_s0>;
+        power-domains = <&power RK3588_PD_NPUTOP>;
+        resets = <&cru SRST_A_RKNN0>, <&cru SRST_H_RKNN0>;
+        reset-names = "srst_a", "srst_h";
+        sram-supply = <&vdd_npu_mem_s0>;
+      };
+    };
+...